About Me


Gavin Hubble - (BSc & Post Grad. Business Marketing) - I started working in the wine industry over 23 years ago in New Zealand. Working in; wine retail, sales, wine production, label & packaging design, marketing, wine buying, consulting and wine education. I am responsible for the Brand Health of 60+ wine brands distributed here in New Zealand. Wine Brands from New Zealand, Australia, France, Italy, Spain, Portugal, Chile and Argentina. I work closely with the Trade Industry - (Retail Stores & Restaurants) introducing, educating and positioning exciting and unique brands to wine enthusiasts all over the world.

Tuesday, June 26, 2012

Florio Marsala - Sicily/ Italy

After a lengthy journey from Auckland to Palermo in Sicily/ Italy - I was informed that the trains to Marsala on the far north-western tip of the island were not working. I had to wait for a local bus to make the trip across the island arriving in the early evening. So I quickly checked in to my hotel, and found a lively wine bar nearby to immerse myself into the local culture, and what better way here in Italy than to watch the national football team play in Euro 2012. The next morning I made my way to Florio Marsala located just on the edge of town, which is an icon of Marsala and Sicily, plus an imposing building built some 100 meters from the deep blue Mediterranean Sea.

 

The history of Marsala is among the most amazing I know, not only because it is a wine discovered as an accidental effect by its inventor, but also for the fact it is one of Italy’s finest wines. Today Marsala is living a new lease on life, where quality is finally the main characteristic of this wine, leaving in the past the errors and mistakes made by many producers for too many years. In the course of the last twenty years, producers made considerable efforts in order to finally give back to Marsala the dignity this great wine deserves, as well as giving more attention on the vinification practices and quality.
Vincenzo Florio was the first Italian to establish a winery dedicated to the production of this unique wine. In 1773, because of a storm at sea, the English merchant John Woodhouse was forced to land at the port of Marsala, instead to the one of Mazara del Vallo, where he was sailing. When he landed, he entered a tavern in search of refreshments and here he had the chance to try the local wine. In fact they served him some perpetuum, the wine traditionally produced at Marsala. Perpetuum - or perpetuo (literally, perpetual) - was produced by filling the barrel with wine from the latest harvest and then drawn off according to need, the barrel was then refilled - which contained some of the wine of all the preceding vintages - with the new. A wine therefore undergoing a natural oxidation process according to its progressive emptying and taking ‘new life’ with the adding of the wine from the new vintage.

 

John Woodhouse enjoyed the wine, plus it reminded him the famous wines of Madeira and Jerez, being much appreciated in his homeland. Being an astute merchant, he decided to ship some of this wine to England while hoping to start a thriving trade. As Woodhouse knew of the adverse conditions the wine would suffer in the holds of ships, he decided to add some brandy to each barrel in order to ensure better travels. Woodhouse returned to England with his precious cargo and, when he arrived, he realized the reinforced wine had become better than when he left Sicily: it was an dramatic success. Woodhouse then returned to Sicily and established his winery, in a few years his Marsala wine became successful in England and it soon become the wine mainly consumed in the ships of her Majesty's fleet. It is said Horatio Nelson - who particularly appreciated Marsala - used to celebrate the victories in his battles with this wine, and for this reason it was called ‘victory wine’.
At the beginning of the 1800s, two Englishmen, encouraged by the success of Woodhouse, entered the history of Marsala: Benjamin Ingham and his nephew John Whitaker who established Ingham winery near the one of Woodhouse. In 1832 the first Italian entered the scene -  Vincenzo Florio a skilled merchant from Bagnara Calabra, a successful merchant of spices and descendant from one of the most prestigious and rich Italian family of the time - who decided to establish his winery between Woodhouse and Whitaker. The contribution of Vincenzo Florio for the development and the image of Marsala was remarkable. Thanks to this, Marsala soon changed its image and from wine destined for the sailors of the English fleet, it became a wine appreciated and looked for in the noble courts all over Europe. The skill and the success of the Florio family and their wines seemed unstoppable and in 1904 they establish, together with other entrepreneurs of Marsala, S.A.V.I (Società Anonima Vinicola Italiana, Anonymous Italian Wine making Society) which in few years acquires the wineries of Woodhouse and Ingham-Whitaker.

 

In 1924, the Florio family decides to sell the winery of Marsala to Cinzano, another important family in the history of Italian wine. In the course of World War II, because of the bombing raids of the allied aviation, Florio cellars were severely damaged (as you see from my photo above, the oldest vintage now left is from 1939), and the restoration of the winery took a very long time, and only in 1984 was restoration completed. In January 1998 the control of Florio winery passes to ILLVA Saronno Holding, which in 1987 already owned the 50% of the firm's shares, therefore beginning a new and important chapter of this historical winery. Important and fundamental changes in the production and commercial management - contributing to the rebirth of Marsala Florio - as well as to the qualitative image of Marsala in general - by adopting scrupulous selections in every phase of production and by introducing productive criteria at very high levels. Marsala is today living again the glorious events of its history and the Florio name is everywhere in the world the synonym of quality Marsala.
During my visit at Florio - I had the pleasure to go through all the cellars seeing the whole process and careful ageing in the specifically designed barrels for the development of each of the Marsala wines. Every detail - from the purposely constructed, though subtle slope of the cellars so the seas breeze can enter the winery from the front and taking the warm air as it leaves from the top. Keeps the cellars at a constant temperature, plus humidity and dust is removed from the air by the limestone floor. We ended the visit with a tasting in the grand hall at the rear of the cellars.

 

The current production of Florio is divided between excellent Marsala and sweet wines, such as Malvasia delle Lipari, Passito di Pantelleria, Grecale and Morsi di Luce, an excellent wine made from Moscato d'Alessandria, known in Sicily as Zibibbo. Florio is currently producing five different styles of Marsala: Marsala Superiore ‘Vecchioflorio’ - an excellent value wine - Marsala Superiore Riserva Targa, Marsala Vergine Terre Arse, the excellent Marsala Vergine Baglio Florio and, the last born, Marsala Superiore Riserva Donna Franca, a tribute to Donna Franca Florio, a prominent figure of belle époque, as well as woman of refined class and beauty. Marsala Superiore Riserva Donna Franca is in fact the last piece of magic created by Carlo Casavecchia, the result of years of researches and studies, which led to the creation of this charming and smooth wine which will certainly be capable of satisfying the senses of the most exacting enthusiasts.
Each Marsala has its own indisputable class and elegance; the next few days was a continuous discovery made of aromas and emotions, the confirmation of the quality Marsala Florio has been able to achieve in the course of its long and prestigious history. Even though it was a journey - and I can say this now with a smile on my face. It is definitely worth the effort - please be clear, don’t take this journey lightly, but when you are here and you enjoy the wines, paired with the local cuisine looking out to the Mediterranean Sea, it doesn’t get much better than this.

Monday, June 25, 2012

Montes 'Alpha' Cabernet Sauvignon 2009

Grape Variety: 90% Cabernet Sauvignon, 10% Merlot

Growing Region: Apalta vineyard, Santa Cruz, Chile

Chief Winemaker: Aurelio Montes

TASTING NOTE:
This is a true expression of quality Chilean winemaking. The fruit is sourced 100% from Montes famous Apalta vineyard, reputed to be the best for red wines - and one of the most recognized wines of Chile. The first wine Aurelio Montes crafted under his new label was the 'Alpha' Cabernet Sauvignon 1987, which became the first premium Chilean export wine and it opened for Montes and for Chile, a path of success, which other wineries quickly followed.
This 2009 expression - after being carefully aged for 12 months in French oak. The wine shows great complexity, balance, with firm tannins and a remarkable personality. In the glass you will be greeted by a rich ruby red coloured wine. The nose shows a mix of elegant and complex aromas of blackcurrant, chocolate, black pepper and cigar box aromas, its affinity with oak lends vanilla and coffee notes, a wine in perfect balance of real finesse and character - and that is just on the nose.
Then on the palate this wine shows great complexity, a full bodied and balanced mid palate, with classical Cabernet characters, with integrated but confident tannins with a full, long and persistent finish. Decant for 45-60mins and serve at 18C.

CELLARING POTENTIAL:
Drinking well this winter season; and will age well for another 7-9 years.

SUGGESTED FOOD MATCHES:
Perfect wine match with wild game, richly flavoured meats dishes with wine jus and roasted vegetables, enjoy.

A wine in perfect balance of real finesse and class.

 



Trichloroanisole

Trichloroanisole (TCA) as it is commonly known - is a small and chemically simple molecule, which is very potent to the senses. TCA can be detected in dry white wine and sparkling wines at levels around two parts per trillion (0.000000000002 grams in a litre of wine), and in red and port wines at around five parts per trillion.
Such low concentrations are difficult to conceptualise but it is similar to one teaspoon in a couple of thousand Olympic sized swimming pools. A single gram of pure TCA could badly taint the entire volume of wine produced in Australia each year. The other less common contributors to cork taint are not much better having sensory thresholds of around 20 parts per trillion.

 

TCA is the natural compound that at higher levels can impart 'musty, tired or dull' flavours and aromas to wines. Wines that contain TCA at a detectable level are described as either being "corked" or having "corkiness."
Cork is a major source of TCA in bottled wine, although experts indicate that TCA in wine may be derived from sources other than cork, such as from wood barrels.
Wineries in most wine-producing countries, along with the cork industry, continue their research efforts to minimize the presence of TCA in wine.
There is no conclusive evidence that wines that exceed any particular level of TCA will result in detectable negative characteristics for any significant segment of the wine-drinking public. Many award-winning wines contain levels of TCA that are detectable by instruments but not by the consumer. There is no single, fixed level of TCA that distinguishes a 'good' wine from a 'bad' wine.
Perception of TCA by consumers is governed by many variables, including alcohol content, wine characteristics, and the sensitivity of the consumer. The consumer threshold of perception of TCA varies dramatically according to experience and inherited genetic capabilities. Research material indicates that the existence of minute traces of TCA in quality wines does not 'always' impair product quality experience.


Monday, June 18, 2012

Barros Tawny 'Special Reserve' Port

Grape Variety: Touriga Nacional, Touriga Franca and Tinta Barroca

Growing Region: Douro Valley, Portugal

Chief Winemaker: Pedro Sá

TASTING NOTE:
Located in the heart of Portugal's famed Douro region, Barros Almeida is one of the largest and most respected Portuguese port houses. Established in 1913, Barros has won an international reputation for producing the finest ports. I made my way to the vineyards last summer and had the most memorable experience, climbing the terraces in 38 degree heat - then sitting in front of the winery overlooking the Douro sampling a range of vintage ports from their cellars.
All of the prime fruit is hand-harvest at the best moment, the grapes are then destemmed, crushed and vinified in a careful maceration with extraction of colour, tannins and aromas. This process takes place until reaching the desired Baume. At this stage grape brandy/spirit is added to halt fermentation and retain natural sweetness. A wine of exceptional quality, crafted by the careful blending of wines with different levels of maturation, ages and variable sources, with a minimum required age of 7 years in oak barrels.
In the glass a bright brown-tawny colour. This port has a complex bouquet of dried fruits aromas, harmoniously combined with wood notes. On the palate this port is velvety and silky, with an excellent deepness. But it doesn't end there as it has a delicious and extremely lingering finish. Serve at a temperature between 12 - 14°C.

CELLARING POTENTIAL:
Drinking perfectly well this winter season; and will age for another 4-5 years.

SUGGESTED FOOD MATCHES:
Perfect wine match with light through to rich and aromatic desserts, and blue cheeses - enjoy.

A real treat for Port enthusiasts.

 


Baumé & Brix

The Baumé scale is a pair of hydrometer scales developed by French pharmacist Antoine Baumé in 1768 to measure density of various liquids. The unit of the Baumé scale has been referred to variously as degrees Baumé. One scale measures the density of liquids heavier than water and the other, liquids lighter than water. The Baumé of distilled water would be 0.
It is convenient because it gives a winemaker an estimate of finished alcohol levels in the grapes.

Each 1 degree Baume = 18 g/L of sugar, and when fermented will result in approximately 1% alcohol.
Both Baume (Bé°) and Brix (°Bx) scales give a measure of soluble solids in grape juice.

At 20°C the relationship between specific gravity (relative density) and degrees Baumé is:
For liquids more dense than water: s.g. = 145 ÷ (145 - degrees Baumé)
For liquids less dense than water: s.g. = 140 ÷ (130 + degrees Baumé)

 

ºBrix is named after Adolf Brix, measure of the concentration of sugar in solution - Indicates potential alcohol that may be achieved. Brix (°Bx) is defined as the percentage of sugar by weight in a solution. Brix scale is important indicator for maturity of the grape. The traditional method for determination of Brix is by using hydrometer, which will measure the density (specific gravity) of the grape juice. The different yeasts strains have different levels of reduction, so they will all convert different percentages of sugar to alcohol.

Expressed as the % by weight of sugar in solution at a specified temperature: 1.8 ºBrix = 1 ºBaume.
1 Brix = 10g/L of sugar. Grapes are generally harvested at 20 to 25 Brix, resulting in alcohol after fermentation of 11.5 to 14 percent.

Currently ºBrix is the best available indicator to determine when grapes are ready for winemaking. These measures are used to determine the date of harvest. As regular measurements of sugar level during the ripening period can determine time of harvest. Most wineries have a minimum ºBrix level to be reached for each variety before processing.

Monday, June 11, 2012

Chapel Hill 'McLaren Vale' Shiraz 2009

Grape Variety: 100% Shiraz

Growing Region: McLaren Vale, South of Australia

Chief Winemaker: Michael Fragos

TASTING NOTE:
If you ever get the chance to explore South Australia, make sure you have on your places to visit Chapel Hill. Not only are the wines outstanding, the setting with the old Chapel/ cellar door and the retreat/cooking school will make it hard to leave.
The grapes for this wine were sourced from vines aged between 16 and 35 years. The individual vineyard parcels were harvested and fermented separately to retain the unique character of each site. After fermentation and careful skin contact the fruit was gently basket pressed, and then matured for 20 months in 300L oak hogsheads, of which 91% was French and 9% American. Barrel ages vary from: 24% new, 11% one year old, 33% two year old, 17% three year old and 15% four year old. To preserve purity and character, the wine is un-fined, with no additions of tannin and is also bottled unfiltered.
McLaren Vale Shiraz is typically graced with an opulently intense mouth feel and a unique combination of power and grace. The 2009 McLaren Vale Shiraz displays a rich mixture of blueberry, pimento and liquorice flavours. The seamless integration and balance of these fruit flavours with the subtle textured oak notes, is further enhanced by the bold persistence and mouth filling savoury tannin structure to the finish, which pleasingly lingers for some time. Decant for 45-60mins and serve at 17C.

CELLARING POTENTIAL:
Drinking well this season; and will age well for another 5-7 years.

SUGGESTED FOOD MATCHES:
Perfect wine match with black olives, flavoursome meat dishes, and aged cheddar, enjoy.

90 points, Wine Advocate, Feb. 2012.
  
 

IGT - (Indicazione Geografica Tipica)

IGT is the third tier in the Italian wine classification system, which stands for Indicazione Geografica Tipica (Typical Geographical Indication) - an IGT classed wine is ‘typical’ of a particular geography or local region. Most IGT wines are simple, made from grapes grown locally and intended to be enjoyed in their youth. You’ll find many IGT wines from Tuscany that are made from Sangiovese, a grape with a long history in the region. In general think of them as an approachable wine - well priced and suitable for everyday drinking with pasta dishes, pizza and bbq’s, but not something that is going age or to take on stronger courses.

 

But there are some exceptions to this, and the best example are Super Tuscan wines that are unique examples, and most are still classed at the IGT level, before they were in the Table Wine category. The results of these wines have been varied. Some are the most expensive wines in Italy such as the famous Tignanello and Sassicaia from the Bolgheri region of Tuscany, but many are more affordable wines, a step up from table wines; good for every day drinking. An IGT wine will say IGT on the label, there are approximately 130 IGTs throughout Italy.
The IGT classification was brought in as part of the 1992 wine legislation which came to be known as the 'Goria Law' - after Giovanni Goria, the then Italian minister for agriculture. Its aim was to accommodate those wines which did not qualify for any of the quality wine designations DOCG & DOC, which are generally intended to protect traditional wines such as Chianti or Barolo. It is considered broadly equivalent to the French vin de pays designation.
IGT wines are listed by the specific region in which they were grown and the grape varietal used that make up 80% of that wine, in that order. This category allowed winemakers to branch out and try new ideas in new regions. They were given the freedom to create and experiment, which has spawned a whole new style of wines. Many international grape varietals are used, and often vinified in the ‘New World’ style of fruit-forward wines.



Friday, June 8, 2012

Winemaker Series:

Welcome to another in the series of winemaker interviews.

Kilikanoon Wines founder, director and senior winemaker Kevin Mitchell grew up in the vineyards of South Australia’s Clare Valley, where his father, Mort, planted and tended vines.
The Kilikanoon property, featuring a 1860s stone cottage housing the Kilikanoon tasting room, was originally settled by early English migrants who named it after an historic old mansion in Cornwall. On purchasing the property in the 1990s, Kevin Mitchell inherited 30 year old Shiraz, Cabernet, Grenache and Riesling vineyards, many of which were planted by his father in the 1960s.
The first Kilikanoon release was in 1998, with a 1997 vintage Shiraz, Cabernet, Grenache and two 1998 Rieslings. Since that time Kevin has continually refined his skills and has produced a wide portfolio of Kilikanoon wines from some of Australia’s finest terroir - carefully chosen to express the individuality of their respective sites.

 

Kevin has an uncompromising approach to quality for all his wines, crafting not only wines that are approachability in their youth but with the potential to age gracefully for many years. I have enjoyed watching this winery develop over the years and sharing Kevin’s wines with enthusiasts here in New Zealand. With such an impressive short history the future is one to keep an eye on.

What first attracted you to the wine industry and as a winemaker?
A number of factors were in play, obviously being part of a grape growing family had a huge influence, however, it wasn’t until I attended Roseworthy Agricultural College where I completed a agricultural science degree that my interest was truly piqued.  I naturally gravitated towards the wine group, they were my kind of people and I really took it from there.

Where and when did you study winemaking?
Once I had my agricultural science degree from Roseworthy Agricultural College under my belt. I went on to study oenology, completing a graduate diploma of wine technology during 1991 and 1992.

What is your favourite grape variety(s) to work with and why?
That would have to be Grenache and Riesling.  In my opinion, these are the ‘most honest’ varieties to work with.  They are vineyard dependent and the hardest two to dolly up!  It’s very difficult to embellish these grapes through tricks, I love the styles that are possible and of course, they are perfect for the Clare Valley.

Which grape variety would you most like to work with in the future and why?
Pinot Noir.  As time has gone on and my own palate has developed I have become a big fan.  It wasn’t always that way, I used to scoff at Pinot, but now, I’m really enjoying good Pinot. It’s hard to grow in Clare but I would love to work with it.

With each new vintage what do you most look forward to?
The end of it!  No seriously, every year provides a blank canvas, every year is going to be the best in 10 years, and the expectation of vintage is the most exciting part.  You can’t predict it and each year is unique.  As a winemaker I learn something new each vintage because one is never the same as the next.

 

To date what has been you most interesting/challenging vintage and why?
[Laughs] The most challenging (worst ever) was probably 2008.  At the outset it was looking like a great year, it seemed that autumn had taken the place of summer; it was too cold for ice cream but great for the grapes.  We experienced a beautifully cool January and February where temperatures never exceeded the mid 20’s (Celsius) for six weeks.  We had just picked most of our whites when in late February the temperature soared.  We suffered through 40+ temperatures 16 days in a row.  We could not pick the remaining fruit fast enough and were juggling to get it into the winery, things got worse day by day.  It was an absolute paradox as it was a fantastic year early on.  However, our whites (Riesling and Semillon) were superb.  They had enjoyed a cool ripening period and picked before hot spell.  We were one of the lucky ones in that regard.

Which person has influenced you the most as a winemaker and why?
That’s a really hard question to answer, but going back to my student days I would have to credit Doctor Andrew Markides who taught amongst other things sensory evaluation. He had a very friendly and encouraging style and his knowledge was incredible.  Professionally it is hard to nail it down to one particular person; our industry has many icons, some of who have resided in the Clare Valley so you don’t have to look far out of the region for inspiration.  But if I had to name an individual it would have to be Brian Croser, he has achieved a lot personally but he is someone who is also a huge advocate for true winemaking.  He has been a driving force in promoting authentic Australian winemaking not only domestically but also internationally.

Which person ‘current’ or ‘past’ would you most like to have met or meet and why?
The late great Mick Knappstein, who through his work as grower really put the Clare Valley on the map.  From all accounts he was a very charismatic character.  His vineyards provided the foundation for the Knappstein dynasty.  Clare wine making really started with Mick.

If you were stranded on a desert island and you could take one bottle of wine with you – what would it be and why?
It’s no secret I am a big fan of Southern Rhone Grenache blends, so perhaps a high end Châteauneuf-du-Pape, or if I was on a budget something from Gigondas.

If you could make wine anywhere else in the world - where would it be and why?
Either Châteauneuf-du-Pape or a region in Burgundy, the holy grail of wine and pinot.  The wine there is made in such small batches and very hard to get.  It would be a joy to be truly immersed in the region to study the winemaking styles, where tradition is revered.  One day…

What advice would you give a young person starting out as a winemaker?
Study accountancy!   If you’re passionate about wine & winemaking you should of course seek to fulfil it.  It’s a wonderful lifestyle, wine is a truly unique product, the vintage variations we discussed earlier are just one factor, the opportunity work internationally and immerse yourself in an entirely different region and work with different varieties adds yet more layers to the tapestry of winemaking.  Not to mention you can travel the world and claim it on your tax!  However taking what you love and making it your career takes on a whole new dimension, I wasn’t kidding when I suggested studying accountancy.

 

If you weren’t a winemaker - what would you like to be and why?
A great philosopher…hmmm… seriously I think I would enjoy being a good shrink! Psychiatry is a fascinating discipline and I think I would enjoy delving a little deeper in the human spirit and psyche.  Human nature is multi-dimensional and who doesn’t want a deeper understanding of it - it’s all a paradox of wine really…

In the future, what exciting changes can you see, or would like to see for your wines, wine styles, vineyard or winery?
At the end of the day, and I think this applies to anyone, I will continue to strive to further refine my own personal style, the same style that has helped Kilikanoon become the successful brand that it is.  I would enjoy the opportunity to delve much deeper into the mystery of terroir.  It’s something we could really explore in the Clare region, especially if the resources were unlimited.
To really truly refine your own winemaking signature as an expression of the terroir and unashamedly stamp your own style on the wines, yes that would be an exciting pursuit.


Kilikanoon Wines are available in New Zealand and around the world from quality wine retailers and restaurants. Or visit their website: Kilikanoon Wines

Monday, June 4, 2012

Domaine Jessiaume Volnay ‘Brouillards’ 1Er Cru 2009

Grape Variety: 100% Pinot Noir

Growing Region: Les Brouillards, Volnay, Burgundy, France

Winemaker: Pascal Jessiaume

TASTING NOTE:
Domaine Jessiaume is a gem that was known by a select group of aficionados, only a few years ago. After several years of new ownership and the creative freedoms that came, winemaker and viticulturist Pascal and Marc Jessiaume who have stayed on - are creating wines that have put all of Burgundy on notice. Following the traditions of the previous 5 generations, combined with modern techniques. They are creating wines with elegance and finesse with supple and well integrated tannins.
Domaine Jessiaume over the years has built a formidable reputation as a small négociants of unparalleled quality; this particular wine will only solidify this position. I have watched these wines closer than many - having the opportunity to visit the estate and sample these wines on a regular basis.
Sourced from an exceptional vintage, this wine has elegance and finesse, the palate is supple with well integrated tannins. This wine has had 12 months in French oak barrels (30% being new oak), this was then followed by approx 5 months finishing in stainless-steel tanks before bottling.
In the glass you have a bright ruby red colour with a purple hue. On the nose dense and powerful notes of ripe fruits and fresh herbs. These notes carry through on to the palate, and are supported with ripe, earthy and expressive red berries, supple and delicate flavours are just shy of being medium weight and culminate in a delicious and well structured finish that lingers. I encourage decanting for 45-60 minutes and serve at 15-17C.

CELLARING POTENTIAL:
Approachable this season; and will age gracefully for another 15-20 years.

SUGGESTED FOOD MATCHES:
Perfect wine match with feathered game, mushroom pasta or risotto, and a mature flavoured cheese, enjoy.

90pts, Wine Enthusiasts, 2011

  

 

Volatile Acidity

Volatile Acidity, also known as VA - is a wine fault, an unpleasant characteristic of a wine. VA can be caused by several acids, even though its primary source is acetic acid and is the result of bacteriological infection through oxidation during winemaking. In quantities of 0.2 to 0.4 g/L, volatile acidity doesn't affect a wine's quality. At higher levels, however, VA can give wine a sharp, vinegary tactile sensation, which is caused by acetic acid. Extreme volatile acidity signifies a seriously flawed wine, and can be referred to as volatile.
The acetobacter bacteria, plus others are found on the surfaces of grapes, plus reside on winery equipment and in used oak barrels. They all have one thing in common. They are aerobic bacteria, needing lots of oxygen to reproduce. They are microscopic single celled organisms which have enzymes that work to oxidise alcohol into the vinegary smelling acetic acid.

 

It can all start in the vineyard. When the grape is damaged by birds or after being infected with moulds such as Botrytis, the juicy parts of the grape are exposed to the air. The grape skin is home to natural populations of yeasts which ferment the exposed juice producing alcohol. The Acetobacter's then use this alcohol to produce acetic acid. When you crush these sorts of grapes, the resultant juice will have a high viable population of Acetobacter, and also a higher than normal level of acetic acid. While the cell counts can be reduced by settling or clarifying the juice prior to fermentation, it is not a particularly good situation to be in if you intend to make a decent wine.
While starting off with healthy undamaged grapes is a good start to making wines with low VA, it is no guarantee. Most acetic infections occur in the winery. The bacteria enjoy living in wines that are both low in acidity and sulphur dioxide. But the key ingredient for their growth is oxygen. Oxygen is also slowly absorbed into the wine through the gaps between the staves in oak barrels. More damaging is when the level of wine in the barrel falls due to evaporation, and this lost wine is not regularly replaced. It is probably true to say, that the most likely time for any wine to become acetic is during its barrel storage, either due to the barrel being ullaged, or its sulphur dioxide levels not being maintained, or both.
Preventing these conditions sounds simple, there are complicating factors. Oxygen is necessary in the natural reactions which soften tannins and stabilise the colour of red wines. Wine yeasts also find it difficult to undertake clean and completed ferments if oxygen levels in the juice are very low. So in many wines, having close to zero dissolved oxygen is not the answer.
Poor bottling practices can also result in acetic wines. Filtration prior to bottling is known to reduce the number of viable acetic acid bacteria. Membrane filtration, in which the wine is passed through a filter with holes smaller than the acetic acid bacteria, is particularly effective. However, if the wine picks up excessive air when it is being bottled, there is a possibility of the wine spoiling after bottling.